In general, a full-color organic EL (electro luminescence) display device includes a substrate on which organic EL elements for colors of red (R), green (G), and blue (B) are arranged as sub-pixels. The organic EL elements are selectively controlled to emit light at an intended luminance with the use of TFTs, and thus an image is displayed on the organic EL display device.
In a process of manufacturing such an organic EL display device, luminescent layers which are made of organic luminescent materials for emitting different colors of light are provided in a pattern for respective organic EL elements which are light-emitting elements. As a method for forming the pattern of the luminescent layers, for example, a vapor deposition method is known in which a vapor deposition mask called shadow mask is used.
Patent Literature 1 discloses a vapor deposition device and a vapor deposition method in each of which a shadow mask is used. FIG. 12 is a plan view illustrating a film formation target substrate and a mask unit which are provided in a vacuum chamber of the vapor deposition device of Patent Literature 1 and are viewed from a film formation target substrate side. FIG. 13 is a cross-sectional view taken along the line B-B in FIG. 12 and schematically illustrating main parts of the vapor deposition device of Patent Literature 1.
As illustrated in FIGS. 12 and 13, a vapor deposition device 250 of Patent Literature 1 includes a vacuum chamber 260, a mask unit 280, and a substrate moving mechanism (not illustrated). The mask unit 280 includes a shadow mask 281 and a vapor deposition source 285 (see FIG. 12).
The shadow mask 281 has a plurality of openings 282. The vapor deposition source 285 separately contains vapor deposition particles which correspond to each color so that a luminescent layer of the corresponding color is formed. Further, the vapor deposition source 285 has a plurality of injection holes 286 through which a vapor deposition material is injected as vapor deposition particles.
As illustrated in FIG. 13, a film formation target substrate 200 is held so that a gap g1 between the film formation target substrate 200 and the shadow mask 281 becomes constant, and the vapor deposition source 285 is provided so as to face the shadow mask 281 via a constant gap g2.
In the vapor deposition device of Patent Literature 1, the film formation target substrate 200 is moved relatively to the mask unit 280 in a direction of the arrow in FIG. 12 such that the vapor deposition particles injected from the plurality of injection holes 286 of the vapor deposition source 285 are sequentially deposited in a vapor deposition region 210 on a vapor deposition surface of the film formation target substrate 200 via the plurality of openings 282 of the shadow mask 281. Thus, a pattern of vapor-deposited films 211 which correspond to respective sub-pixels is formed in the vapor deposition region 210 of the film formation target substrate 200.
[Patent Literature 1]
Pamphlet of International Publication No. 2011/034011 (Publication date: Mar. 24, 2011)
[Patent Literature 2]
Japanese Patent Application Publication Tokukai No. 2011-233521 (Publication date: Nov. 17, 2011)